How to Learn Most About Your Patients

Clinical scores such as e.g. PASI and SCORAD have a significant overlap but significant disease-specific differences exist, which mean that one must choose (1). Similarly, no one would accept replacing measurements of haemoglobin with reticulocyte counts, although the two are sometimes related. When collecting data using questionnaires the same stringency should therefore be respected. Questionnaires are extensively validated, but the validation is only relevant when a questionnaire is used according to its purpose.

In this issue of Acta D-V, Professors Finlay, Salek and Piguet (2) therefore remind us about something very important. Although apparently easy to use, questionnaires are similar to other measures. Scientifically speaking, such they may therefore be compared more broadly with other methods in order to triangulate their relative contribution to our understanding of a given problem. If you want to study a specific aspect of a disease using a questionnaire, you should use validated tools suitable to answer the research question at hand (3–6). On the other hand, if you want to explore a given disease in the absence of a specific validated questionnaire one must acknowledge that not all methods will give answers of the same validity – they may however help generate a hypothesis.

Gregor Jemec

Section Editor

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